Changelog (v5.4.0-BETA3...v5.4.0-RC1)

• security #cve-2021-41268 [SecurityBundle] Default signature_properties to the previous behavior (@wouterj)
• security #cve-2021-41267 [HttpKernel] Fix missing extra trusted header in sub-request (@jderusse)
• security #cve-2021-41270 [Serializer] Use single quote to escape formulas (@jderusse)
• bug [Console] Add Suggestion class for more advanced completion suggestion #44230 [Console] Add Suggestion class for more advanced completion suggestion (@wouterj)
• bug [Cache] fix connecting to local Redis sockets #44232 [Cache] fix connecting to local Redis sockets (@nicolas-grekas)
• bug [HttpClient] fix closing curl multi handle when destructing client #44204 [HttpClient] fix closing curl multi handle when destructing client (@nicolas-grekas)
• bug [Process] exclude argv/argc from possible default env vars #44208 [Process] exclude argv/argc from possible default env vars (@nicolas-grekas)
• bug [VarExporter] fix exporting declared but unset properties when __sleep() is implemented #44188 [VarExporter] fix exporting declared but unset properties when __sleep() is implemented (@nicolas-grekas)
• bug [Console] Default ansi option to null #44176 [Console] Default ansi option to null (@jderusse)
• bug [WebProfilerBundle] Fix JS error when toolbar is reloaded #44179 [WebProfilerBundle] Fix JS error when toolbar is reloaded (@jderusse)
• bug [Security] Guard is incompatible with Symfony 6 #44172 [Security] Guard is incompatible with Symfony 6 (@derrabus)
• bug [HttpClient][Mime] Add correct IDN flags for IDNA2008 compliance #44119 [HttpClient][Mime] Add correct IDN flags for IDNA2008 compliance (@j-bernard)
• bug [WebProfilerBundle] Prevent installation of incompatible mailer component versions #44139 [WebProfilerBundle] Prevent installation of incompatible mailer component versions (@Anne-Julia Seitz)
• bug Allow autodetecting mapping type for any object #43917 Allow autodetecting mapping type for any object (@franmomu)
• bug [Yaml] properly parse quoted strings tagged with !!str #44131 [Yaml] properly parse quoted strings tagged with !!str (@xabbuh)
• bug [TwigBridge] do not merge label classes into expanded choice labels #42323 [TwigBridge] do not merge label classes into expanded choice labels (@xabbuh)